WORM_BRONTOK.IL
Win32.Brontok.AB@mm (Bitdefender), Worm:Win32/VB (Microsoft), Worm.Win32.VB.cp (Kaspersky), Win32/VB.NFC worm (NOD32), Worm.Win32.VB.cp (Ikarus)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It modifies certain registry entries to hide file extensions.
It does not have any backdoor routine.
It does not have any downloading capability.
It does not have any information-stealing capability.
It modifies certain registry entries to hide Hidden files.
TECHNICAL DETAILS
128,000 bytes
EXE
01 Mar 2013
Displays message boxes
Arrival Details
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This worm drops the following copies of itself into the affected system and executes them:
- %Windows%\windows.exe
- {drive letter}\{Folder Name}\{Folder Name}.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It then creates the following non-malicious file(s):
- %Windows%\xp.dll
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
isass = "%Windows%\WINDOWS.exe"
Other System Modifications
This worm modifies the following registry entries to hide file extensions:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"
(Note: The default value data of the said registry entry is 0.)
Backdoor Routine
This worm does not have any backdoor routine.
Download Routine
This worm does not have any downloading capability.
Information Theft
This worm does not have any information-stealing capability.
Other Details
This worm modifies the following registry entries to hide Hidden files:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
NOTES:
It displays a messagebox with the following details:
Title: OI DAB!!!
Icon: Information
Body: NAMA :{variable 1}pesan :{variable 2}
Where {variable 1} is any of the following:
- ACHMAD MULTAZAM
- ADI JAYUSMAN
- BAGUS SUPARTONO
- DJANAN ZAMZAMI
- EDI DWI DARYAPTO
- ERWAN HERMAWAN
- RICKY ARDIANSYAH
- SUPRIYANTO
Where {variable 2} is any of the following:
- ayo dab cari chatingan lagi
- keep peace
- nggak ada pesen untuk diriku sendiri
- piye kabare parangtritis
- waduh tepo yo keno to
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.300
9.760.03
01 Mar 2013
9.761.00
02 Mar 2013
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Identify and terminate files detected as WORM_BRONTOK.IL
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
Restore this modified registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: HideFileExt = "1"
To: HideFileExt = "0"
- From: HideFileExt = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = "1"
- From: Hidden = "2"
Step 4
Search and delete this file
- %Windows%\xp.dll
Step 5
Scan your computer with your Trend Micro product to delete files detected as WORM_BRONTOK.IL. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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